1. Field of the Invention
The present invention relates to a flexible display device and a method of manufacturing the same, and more particularly, to a flexible display device capable of preventing image quality deterioration caused by external noise and a method of manufacturing the same.
2. Discussion of the Related Art
With the advent of the information era, the field of displays that visually express electric information signals has rapidly developed. Correspondingly, diverse research is being conducted into flat display devices having excellent performance, such as slim design, light weight, and low power consumption.
Examples of flat display devices may include liquid crystal display (LCD) devices, plasma display panels (PDPs), field emission display (FED) devices, electroluminescent display (ELD) devices, electro-wetting display (EWD) devices, and organic light emitting display (OLED) devices. Such flat display devices essentially include a flat display panel for realizing an image.
The flat display panel is configured such that a pair of substrates opposite to each other are bonded to each other while interposing a light emitting material or a polarizing material therebetween.
Recently, as a flat display device, a flexible display device that includes a flexible substrate formed of a soft material such as plastic and metal and maintains display performance even after being bent like paper has been implemented. Since such flexible display devices have a broader range of applications than conventional display devices not having flexibility, research into commercializing flexible display devices has been conducted.
However, as a substrate formed of a soft material is flexible, careful attention is required to perform deposition of thin films, patterning, and the like to form a cell array and a light emitting structure thereon with a process error less than a critical point. Thus, a sacrificial substrate is generally used for processing convenience. According to a method of manufacturing a conventional flexible display device, processes of depositing and patterning thin films, and the like are performed to form a cell array and a light emitting structure using a sacrificial substrate, the sacrificial substrate is removed, and a substrate formed of a soft material is adhered thereto instead of the removed sacrificial substrate.
Meanwhile, since flat display devices such as flexible display devices including a cell array and a light emitting structure including thin films, image quality may be deteriorated due to external noise.
FIG. 1 illustrates image quality deterioration of a flexible display device caused by external noise according to related art.
As illustrated in FIG. 1, when external noise, such as contact, is applied to a flexible display device, spots influenced by external noise and marked with dashed lines are clearly recognizable. Accordingly, image quality deterioration may be identified.
Thus, a general flexible display device includes a conductive metal substrate connected to an external ground voltage source in order to block influence of external noise on image quality. In this case, a process of connecting the metal substrate to the external ground voltage source is further required after attachment of the metal substrate, and the flexible display device has increased thickness, decreased flexibility, and increased weight due to the metal substrate. In addition, since the metal substrate is reflective, it is not possible to perform foreign matter detection for a cell array and a light emitting array outside the metal substrate.
Alternatively, a general flexible display device includes an insulating plastic substrate, and a conductive film additionally attached to the outside of the plastic substrate and connected to an external ground voltage source to prevent flexibility deterioration and block influence of external noise on image quality. In this case, a separate conductive film needs to be prepared, and a process of attaching the conductive film to the plastic substrate and a process of connecting the conductive film to the ground voltage source are further required. As a result, manufacturing time and manufacturing costs are increased.